A Norquist signer, Fleischmann declined to comment Monday. However, last week his office issued a written statement that said the congressman "thinks that we must first have real spending cuts before revenue is even put on the table."

Sponsored by Norquist's conservative lobbying organization, the pledge has played an outsized role in Washington's "fiscal cliff" negotiations. Popular among Republicans, the pledge calls for signers to oppose income tax increases for individuals and businesses. It also prohibits reductions of credits and deductions unless they are matched with further tax cuts.

But when it comes to cliff negotiations, Democrats say the pledge prevents Republicans from considering higher taxes on the wealthy as part of a larger deficit reduction deal. Republicans counter that more revenue isn't the solution; they accuse Democrats of not being serious about cutting entitlement programs.

Most House Republicans, including U.S. Reps. Scott DesJarlais, Tom Graves and Fleischmann, have shown no sign of backing down from the Norquist pledge. But Corker, Alexander, Georgia Sen. Saxby Chambliss and several other Republican senators have said they're no longer bound to it.

Cliff negotiations remain in flux as both sides posture. If a deal isn't reached by the end of the year, a $500 billion combination of tax increases and spending cuts automatically will go into effect.